Method for increasing battery capacity by using silicon anode material

Unlike the current production method of lithium batteries using graphite as a negative electrode, the Japanese lithium battery industry has set off a climax to increase the capacity of lithium batteries, and the specific measure is to rely on silicon negative electrodes.

GS Tangshao Company has trial-produced a lithium iron phosphate battery , in which lithium carbonate is used as a negative electrode to improve battery life, and silicon as a negative electrode can increase battery capacity. It can be proved by experiments that compared with the graphite negative electrode. The remaining capacity of the battery after 300 cycles of use is nearly doubled, from 40% to about 80%. In addition, the silicon negative electrode lithium battery has good low-temperature performance and can also increase the battery capacity. A successful case of silicon negative electrode, there is a shallow lithium battery used in Mitsubishi Motors for electric vehicles, and a silicon nano negative electrode material for Hitachi Maxell in the field of consumer electronics.

The appearance of silicon nanomaterials is determined by the physical properties of silicon. Although silicon can store 10 times more energy than graphite, the volume difference between expansion and contraction is up to 4 times, and as the number of uses increases, the electrode material The bonding force between the furnace and the electrode material and the current collector is weakened, thereby affecting the performance of the lithium ion battery.

Japanese lithium battery research experts believe that the solution to this problem is theoretically to increase the spacing between silicon ions, but if it is excessively expanded, the movement of electrons and lithium ions will decrease and the battery performance will decrease. This problem was first solved in the field of consumer lithium-ion batteries in Maxell's, that is, the silicon particles were reduced to nanometer size and mixed with graphite. The use of silicon-based materials ensures the same capacity when using graphite, but the capacity after 500 cycles is significantly improved.

Another silicon negative lithium battery manufacturer, Mitsui Metals, is determined to apply this lithium battery application to both consumer electronics and electric vehicles. The goal is to be practical in the consumer sector in 2012 and to use it as a vehicle- powered lithium battery in 2015.

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